Build a mansard loft conversion in West Sussex from £51,744

Mansard loft conversions are ideal if you want to maximise the space in your home. Extending your roof out into a flat roof with an almost vertical wall, they almost always require planning permission but can add significant value to your home. To see prices and availability for your job click green button.

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From £52,120

Last active Nov 26
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C C OLEARY CONSTRUCTION

Experienced extension builder ready to quote for your work. C C OLEARY CONSTRUCTION is the best extension builder in West Sussex. No obligation fre...

From £52,200

Last active Nov 26
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Alan Pacy Builder

Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

From £51,880

Last active Nov 26
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Stretch My Home Ltd

Trusted and professional extension builder in West Sussex. Experienced in all extension buildering work and keeping within budget and on quote. Str...

From £51,776

Last active Nov 26
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M Wesley General Builder & Property Maintenance

M Wesley General Builder & Property Maintenance is a trusted extension builder serving customers in West Sussex and the surrounding area. Contact u...

From £51,984

Last active Oct 26
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FIRST FORMAT BUILDING

Need to find an Extension Builder near you for all your extension buildering work?

FIRST FORMAT BUILDING provides a local, trusted extensio...

From £51,992

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H P Building Services Sussex

Member since August 2026

H P Building Services Sussex is a one-stop solution for all your extension buildering needs. Establish over 10 years ago and covering 20 miles arou...

From £52,112

Last active Sep 26
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Haynes & Scott Developments

Relax... you have found a reliable extension builder in West Sussex. Haynes & Scott Developments is a friendly and reliable company based in West S...

From £51,776

Last active Jun 26
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S J Peace Building Contractor

Trusted and professional extension builder in West Sussex. Experienced in all extension buildering work and keeping within budget and on quote. S J...

From £51,744

Last active Jun 26
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ONE BUILD

Relax... you have found a reliable extension builder in West Sussex. ONE BUILD is a friendly and reliable company based in West Sussex who consider...

From £51,936

Last active May 26
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ACF Carpentry Ltd

ACF Carpentry Ltd is an established and experienced local extension builder in West Sussex. Please contact us for a free, no obligation quote and c...

Mansard loft conversion cost in West Sussex

Estimates for build a mansard loft conversion near West Sussex

Mansard loft conversions range from the cheapest installation of £51,744 (ONE BUILD based in BN17) to the dearest of around £52,200 (Alan Pacy Builder based in BN12).

While these estimates give you a good idea how much you'll pay for a mansard loft conversion, the only way to get an accurate price is to get real quotes from real builders.

Get quotes to install a mansard loft conversion in West Sussex by posting a job with HaMuch and we'll send it to extension builders in West Sussex. 


Estimates for common extension builder jobs in West Sussex;

Whether you’re looking to extend your kitchen with a side return extension or you want to convert your basement into a liveable space, read our cost guides to get an idea of how much each project costs before getting a more accurate quote from our database of reliable tradespeople.

More extensions & conversions cost guides...